While various apparatus for use in fusing toner to a sheet of transport material are known, hot roll fusers are preferred for their electrical efficiency. A problem to be solved, however, is the consistent and reliable release of a sheet from the hot or cold roll as the sheet's leading edge emerges from the fusing nip.
The use of sheet detach means and/or sheet transport channels, downstream of the fusing nip, is known to be desirable in achieving good sheet release. However, these desirable mechanisms increase the complexity of clearing a jam which may occasionally occur in this portion of the copier. To aid in jam clearance the fuser assembly may be mounted on rails, such that it can be withdrawn from the copier to a more accessible position.
The present invention provides a single-handle jam clearance apparatus which is accessible only when the fuser assembly has been withdrawn to its inoperative, jam clearance position. This handle, in one position, locks the aforementioned sheet detach means and sheet transport channel in their operative position, closely adjacent to the output or downstream side of the fusing nip. When the handle is manually moved or unfolded to its jam clearance position, these mechanisms are moved out of the way, thus exposing the fusing nip and the mechanisms for convenient manual jam clearance.
Prior art means are known to facilitate jam clearance in fusers. For example, radiant fusers are known wherein a sheet transport vacuum plenum is pivotally mounted such that the manual release of latches operates to expose the interior of the fuser. In another device, such a fuser is mounted on slides to permit removal, repair or replacement.
In addition, a hot roll fuser is known wherein the fuser assembly is removably supported by upper and lower slides or rails to facilitate movement of the fuser out of the copier.
While jam clearance has been addressed when designing prior art fusers, as above exemplified, prior to the present invention, no means has been provided whereby a simple, single-hand operation of a jam clearance handle either located and locked various sheet handling devices closely adjacent to a hot roll fusing nip, or simultaneously moved all of these devices away from the nip for ease of jam clearance.